This a tale of two victims of sepsis, the ‘silent killer’ that each year claims the lives of 44,000 people in Britain and leaves another 100,000 with permanent, life-changing injuries, from irreversible damage to internal organs to amputated limbs.One of them is Liz Frood, a 41-year-old mother and Egyptologist at Oxford ­University, who in August 2015 was suddenly struck down with what she thought was a mere tummy bug.The other is Luke Hendrick, a 37-year-old father and drugs and alcohol counsellor from Sidmouth, Devon, who developed a sore throat in July 2014.